In only the third minute Sonko was sent off for conceding his third penalty in four games. The centre-back allowed Benjani Mwaruwari to get goalside chasing Sulley Muntari’s through-ball and when the Pompey striker was impeded, referee Mike Dean awarded the spot-kick and showed Sonko a red card.

However, Niko Kranjcar’s effort struck the post and the 10 men almost snatched the lead at the other end when Bobby Convey popped up in the box, only to screw a good chance wide.

The American was immediately substituted to allow defender Andre Bikey to fill the gap left by Sonko’s sending-off, but within seconds Reading’s other USA international, goalkeeper Marcus Hahnemann, had gifted Pompey a ninth-minute lead.

Muntari’s free-kick into the box should have been an easy catch for the 35-year-old, but he spilled it onto the head of Papa Bouba Diop, with Campbell applying the finish on the line after it had bounced off Kalifa Cisse.

Hahnemann saved from Benjani, Muntari and Kranjcar before Utaka volleyed over as Portsmouth used their extra man to dominate.

Stephen Hunt set up Kevin Doyle for Reading’s best chance, but David James saved with his legs, while at the other end Benjani’s header bounced off the crossbar in stoppage time.

Portsmouth doubled their lead in the 66th minute when Utaka showed astonishing pace to overtake England defender Nicky Shorey in pursuit of Glen Johnson’s through-ball and comfortably round Hahnemann.

Hunt fluffed the chance of a consolation when he missed his kick from Doyle’s pass, before Muntari’s low drive missed by a matter of inches.